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Two-thirds of cancers are caused by random DNA errors during cell division, according to new research.

Environmental factors such as smoking play a lesser role in the development of cancer than previously thought, according to a new study published in the journal Science.

Researchers at John Hopkins University studied health records from 69 countries to establish the relationship between cell division and the risk of 17 types of cancer.

In contrast to previous research which found that a majority of cancers are caused by extrinsic factors, the new study has found that 66 percent of cancers are caused by random mistakes in DNA replication during cell division.

Another 29 percent are caused by environmental factors and just 5 percent of mutations are inherited, the scientists discovered.

“Every time a perfectly normal cell divides, as you all know, it makes several mistakes — mutations,” explained Dr. Bert Vogelstein, co-author of the study.

“Now most of the time, these mutations don’t do any harm. They occur in junk DNA, genes unrelated to cancer, unimportant places with respect to cancer. That’s the usual situation and that’s good luck.”

However, occasionally one of these random mutations will occur in a gene which is a “driver” for cancer.

“That’s bad luck,” Vogelstein said.

However, the researchers said their findings shouldn’t discourage people from striving to lead a healthy lifestyle in order to lower their risk of cancer. Rather, they may provide some explanation for people who have led a healthy lifestyle but still go on to develop cancer.

“It’s not your fault,” Vogelstein said. “Nothing you did or didn’t do was responsible for your illness.”

These mutations seem unavoidable at present, but scientists say that developments in genetic engineering might be able to prevent them in the future. In theory, introducing more efficient repair genes into the nuclei of somatic cells could reduce the effects of these cancer-causing DNA mutations.

The findings in a new study raises concerns about the potential role of infectious diseases as another major stress factor for the struggling population of endangered Puget Sound orcas.

Those orcas’ breath samples revealed microbes capable of causing diseases. Some were resistant to multiple antibiotics frequently used by people and animals, suggesting human waste contaminating the marine environment, according to a study published online Friday in the journal Scientific Reports.

Scientists followed the whales as they swam in Washington state waters and waited for them to surface and exhale. The researchers on boats would swing a 25-foot long pole with several petri dishes above an orca’s blowhole, capturing the droplets that sprayed out.

Using those unique breath samples captured over a four-year period, the study identifies an array of bacteria and fungi contained in the exhaled breath of the small, distinct population of southern resident killer whales of the northeast Pacific Ocean.

The number of Puget Sound orcas has fluctuated in recent decades as they have faced threats from lack of prey, pollution and noise disturbance from vessels. The orcas were listed as endangered in 2005, and now number 78.

Scientists also found healthy bacteria in the breath samples but also worrisome drug-resistant ones such as salmonella and Staphylococcus aureus.

The whales swim through urbanized waterways and encounter a number of environmental stressors caused by humans, including everything from what gets flushed down toilets to agricultural runoff.

“They’re recruiting the bacteria in their habitats,” said Stephen Raverty, the study’s lead author who is a veterinary pathologist with British Columbia Ministry of Agriculture, Animal Health Centre in Abbotsford.

Orcas with weak immune responses can be more susceptible to bacteria resulting in respiratory disease.

“These animals are subject to many stressors, which reduce the competence of their immune systems,” said marine mammal veterinarian Pete Schroeder, co-author of the paper.

It’s the first such study to provide a snapshot of the pathogen burden of this endangered population. It will also help scientists develop a baseline to compare changes to the whales’ respiratory conditions over time.

Scientists collected 26 breath samples from whales around San Juan Island and compared them to seawater samples collected from the millimeter-thick layer on the surface of Puget Sound. When the whales break through the surface of the water, they take in the contaminants and other microorganisms in that sea layer. Pathogens and antibiotic-resistant bacterial strains were found in both the breath samples and seawater.

Scientists don’t know enough to say how harmful the microbes are to the orcas.

“Because you find a potential pathogen, it doesn’t mean the animal is necessarily sick. It might be something normal,” said Linda Rhodes, supervisory research microbiologist with the Northwest Fisheries Science Center in Seattle and co-author.

Bacteria are there, and if for any reason the animals become immune-suppressed, it could provide an opening to make the orcas sick, Raverty said.

Scientists tracking deaths of whales found that respiratory disease was a factor in those animals. About 40 percent of those animals had some infection in the lung, and in some cases, it was strong enough to contribute to their deaths, he said.

The study said it is noteworthy that within 30 miles of the study area, the city of Victoria, British Columbia, does not have a secondary sewage treatment facility, and instead discharges waste with only primary treatment into the Salish Sea.

Scientists are working on creating personal health records for each endangered whale, which are intensely tracked and photographed. Individual Puget Sound orcas are identified by unique black and white markings or variations in their fin shapes, and each whale is given a number and a name.

Making home-cooked dinners and switching off the television while eating could go hand-in-hand with fighting obesity, according to new research in the United States.

The new study, carried out by Ohio State University, looked at 12,842 participants who said that they’d eaten at least one family meal in the week prior to their interview.

One third of the study participants were obese, with obesity calculated from self-reported height and weight measures collected in the survey and defined as a body mass index at or above 30.

After taking into account factors such as employment status, marital status, race, education and age, the researchers found that adults who reported never watching TV or videos during family meals had a significantly lower chance of obesity compared to those who always watched something during mealtimes.

Around a third of participants reporting that they watched TV or videos most of the time during family meals, with 36 percent reporting that they never watched anything during mealtimes.

Those whose ate home-cooked family meals also had lower odds of obesity than other adults who ate some or no home-cooked meals.

More than half of participants reported eating family meals on most days, 35 percent on some days and 13 percent a few days per week. However, the frequency of family meals did not make much of a difference to obesity risk.

The study also found that the lowest odds of obesity were found for adults who engaged in both healthy practices—eating home-cooked food and eating without a TV or video on—every time they ate a family meal.

Commenting on the results lead author Rachel Tumin said, “How often you are eating family meals may not be the most important thing. It could be that what you are doing during these meals matters more.”

“This highlights the importance of thinking critically about what is going on during those meals, and whether there might be opportunities to turn the TV off or do more of your own food preparation.”

However, Tumin also added that although the frequency of eating together as a family was not found to be a contibutor to obesity, family meals can still offer other perks, including social and emotional health.

The study can be found published online in the Journal of the Academy of Nutrition and Dietetics.

The World Health Organization estimates that 50 percent of the population will suffer from at least one allergy by 2050. Relaxnews spoke with Christine Rolland, director of the French association Asthme & Allergies, to help sort fact from fiction when it comes to allergies.

More people suffer from allergies in spring than in winter.

False. People suffer from allergies all year long. You can be allergic to dust mites, animal hair, mold, foods or drugs, or have allergic asthma or skin reactions.

More people have allergies in the countryside than in urban areas.

False. Allergies are more common in urban settings, notably due to a convergence of factors. One of those factors is air pollution, which also aggravates pollen allergies.

Allergies are increasingly common due to environmental factors.

True. One theory suggests that reduced biodiversity in our environment could cause changes to the body’s intestinal and respiratory flora. This could, in turn, reduce tolerance, which ultimately defines an allergy. But there are other factors at play in the development of allergies, such as cigarette smoke (active and passive smoking), other types of indoor and outdoor atmospheric pollution, and changing dietary factors.

A skin-prick test can identify what you’re allergic to.

True. Together with detailed questions about when allergic symptoms arise, skin-prick tests and, if necessary, an “allergen-specific IgE” blood test can help identify the allergen or allergens responsible. These tests can be carried out from an early age.

Indoor air is less polluted than outdoor air.

False. The indoor environment is five to 10 times more polluted than outdoors. In enclosed spaces, several allergens can provoke allergic reactions (dust mites, animal hair, mold, etc.). These are accompanied by the “domestic pollutants” used every day in indoor spaces (smoking, cleaning products, air fresheners etc.). These pollutants can make the occupants of the space more vulnerable and increase the risk of developing allergy symptoms.

Older people can’t develop allergies.

False. Contrary to popular belief, allergies can also develop in older people, at age 60 or even older. Unfortunately, their symptoms are often attributed to causes other than allergies, delaying treatment and the effective management of symptoms.

True and false. Treatment with antihistamines can bring effective relief from allergy symptoms, but this isn’t always sufficient. Depending on the type and severity of the allergy, allergen immunotherapy (desensitization) may be necessary.

A new study has found Parkinson’s patients who do 2.5 hours, or 150 minutes, of exercise a week can slow down the effects of the condition.

Parkinson’s disease (PD) is a progressive condition that often results in impaired mobility, a decrease in health-related quality of life (HRQL), and death.

Previous research has also provided evidence that physical activity can delay this progressive decline.

The new study, carried out by Northwestern University and Rehabilitation Institute of Chicago, looked at 3,408 participants who had provided data over a two-year period, with information collected during at least three clinic visits.

At each visit the team measured physical activity by patients’ self-reports on how many hours of exercise they did each week.

The results showed that those with Parkinson’s disease who partook in 150 minutes of exercise each week had a smaller decline in quality of life and mobility over the two years compared to those who didn’t exercise or exercised less.

In addition, declines in HRQL and mobility were significantly slower not only for those who exercised regularly at the start of the study, but also for those who started to exercise later, after their first study-related visit.

“The most important part of the study is that it suggests that people who are not currently achieving recommended levels of exercise could start to exercise today to lessen the declines in quality of life and mobility that can occur with this progressive disease,” added lead investigator Miriam R. Rafferty.

The team also found that increasing exercise by 30 minutes per week was associated with even slower declines in HRQL in those with advanced PD. The team now believe that these findings could have significant implications for making exercise and physical activity more accessible to people with more severe disability, as the mobility impairments of those with advanced PD may limit their access to regular exercise in community and group exercise programs.

Although the study did not look at which type of physical activity is best, it does suggest that any form of exercise is better than no exercise as long as it is done in a “dose” of at least 150 minutes per week.

“People with PD should feel empowered to find the type of exercise they enjoy, even those with more advanced symptoms,” added Dr. Rafferty.

The results of the study can be found published in the Journal of Parkinson’s Disease.